Method, apparatus and system for flow distribution through a heat exchanger

ABSTRACT

A method, apparatus and system are described for flow distribution through a heat exchanger. The system may include a chassis and an apparatus. The apparatus may include a heat exchanger, and a cold plate. In some embodiments, a pump may provide for the flow of the fluid between the heat exchanger and the cold plate. In some embodiments, the heat exchanger may include a tube to transport a first fluid, a plurality of fins coupled to the tube to facilitate transfer of thermal energy from the first fluid to the plurality of fins, and a gate coupled to the plurality of fins to direct flow of a second fluid through passages between the fins, where the gate includes a deformable laminate of a plurality of layers having different coefficients of thermal expansion, the plurality of layers being bonded to one another. Other embodiments may be described.

BACKGROUND

1. Technical Field

Some embodiments of the present invention generally relate to cooling systems. More specifically, some embodiments relate to flow distribution through a heat exchanger using a deformable laminate gate.

2. Discussion

In recent years, developments in electronic components, such as processors or cores with one or more processors for computing systems or chipsets, have been made to meet increasing demands for better performance and reduced size. These demands have led to a decrease in the weight and an increase in the density of components. These factors lead to increases in heat generation. Particularly in mobile computing environments, these factors can lead to overheating, which may negatively affect performance, and can significantly reduce battery life.

The above results in an increase in the need for effective cooling for electronic systems. Two types of cooling are generally implemented, either alone, but often in combination: air and liquid. In air cooling, a blower, typically a fan, moves air over a heat exchanger's surface. In liquid cooling, a heat exchanger may be implemented to remove heat from the liquid, which indirectly removes heat from the electronic components. Also, pumped loops have been proposed for achieving higher heat dissipation rates at a hot spot, such as an electronic component.

Therefore, there is a need for alternative heat exchangers for systems, such as computer systems. In particular, there is a need for cooling systems that, at least, enhance heat exchanger performance.

BRIEF DESCRIPTION OF THE DRAWINGS

Various advantages of embodiments of the present invention will become apparent to one of ordinary skill in the art by reading the following specification and appended claims, and by referencing the following drawings, in which:

FIG. 1 is an illustrative example of a heat exchanger according to some embodiments of the invention;

FIG. 2 is an illustrative example of multiple heat exchangers according to some embodiments of the invention;

FIG. 3 is a cross-sectional diagram of a cooling apparatus with a heat exchanger according to some embodiments of the invention;

FIG. 4 is a cross-sectional diagram of a system, such as a computer system, with a cooling apparatus according to some embodiments of the invention;

FIG. 5 includes cross-sectional diagrams of various examples of deformable laminate gates according to some embodiments of the invention;

FIG. 6 shows a flow diagram of the flow distribution process according to some embodiments of the invention; and

FIG. 7 shows a flow diagram of the flow distribution process with multiple gates according to some embodiments of the invention.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

Reference is made to some embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the present invention will be described in conjunction with the embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Moreover, in the following detailed description of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail as not to unnecessarily obscure aspects of the invention.

Some embodiments of the invention are directed to a method, apparatus and system for flow distribution through a heat exchanger. Some embodiments of the system may include a chassis and an apparatus. In some embodiments of the invention, the apparatus may include a heat exchanger, and a cold plate. In some embodiments, the heat exchanger may include a tube to transport a first fluid, a plurality of fins coupled to the tube to facilitate transfer of thermal energy from the first fluid to the plurality of fins, and a gate coupled to the plurality of fins to direct flow of a second fluid through passages between the plurality of fins, where the gate includes a deformable laminate of a plurality of layers having different coefficients of thermal expansion, the plurality of layers being bonded to one another.

In some embodiment, rather than using a first fluid, a solid may be used, such as graphite or other conductive material, to transport heat energy to the heat exchanger.

According to some embodiments, the heat pipe may thermally couple the cold plate to the heat exchanger. According to some embodiments of the invention, the heat exchanger may include a thermally conductive tube, which may be molded into a series of thermally conductive fins and integral mounting features. The conduit of tubing may, for example, be thermally conductive metal tube. However, other type of suitable material that allows the fluids, such as, but not limited to, hot liquid, air or cooling agent to flow through may also be used.

Reference in the specification to “one embodiment” or “some embodiments” of the invention means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrase “in some embodiments” or “according to some embodiments” appearing in various places throughout the specification are not necessarily all referring to the same embodiment.

In FIG. 1, an illustrative example of a heat exchanger 100 is shown, according to some embodiments of the invention. The heat exchanger 100 may include a plurality of fins 102 and a heat pipe 104, in some embodiments. Furthermore, the heat exchanger 100 may include a gate 106A, where the gate 106A includes a plurality of fin-like protrusions 108A, according to some embodiments of the invention. In some embodiments, a second gate or an extension of the first gate may be included on another side of the heat exchanger 100, as shown by gate 106B, with the plurality of fin-like protrusions 108B.

In some embodiments, the heat exchanger 100 may be used in conjunction with a blower, such as, but not limited to a centrifugal blower fan or axial flow fan, in system cooling generally has uniformly spaced fins, as described herein. In some embodiments, non-uniformly spaced fins may also be used with the embodiments of the invention. As one of ordinary skill in the relevant art would appreciate, based at least on the teachings described herein, the fluid, typically air, flowing through the fins of the heat exchanger provide a medium to transfer heat from the heat exchanger. In some embodiments, the heat exchanger 100 may be coupled to a cold plate 110, as shown.

In some embodiments, the gate 108A may have only one protrusion 108A which may be positioned externally to the fins of the heat exchanger 100. Regardless of the number of protrusions, the gate may include a deformable laminate of a plurality of layers, each of the effective layers having different coefficients of thermal expansion. According to some embodiments of the invention, the heat exchanger may provide cooling for a system, such as a computer, personal computer (PC), mobile computer, etc., as one of ordinary skill in the art would appreciate, based at least on the teachings provided herein.

The heat exchanger 100, with gate 106A, may therefore distribute the flow of a fluid, such as air, from fan to the heat exchanger. In other words, the gate 106A may use a heat sensitive, deforming material to form gate within the passages of the fins 102 of the heat exchanger 100 in such way that the gate closes when the heat exchanger temperature is low, according to some embodiments. By blocking airflow for a heat exchanger 100 that may not require cooling, fluid flow, such as air flow, may be directed toward other heat exchangers (see FIG. 2) or it may allow a reduction of blower speed while maintaining a flow rate due to the reduced side of the opening, as one of ordinary skill in the relevant art would appreciate based at least on the teachings described herein. According to some embodiments, this may also enable quieter operation of the fan, especially when the apparatus or system is in a low power condition. This is because the fan may only need to provide airflow to the heat exchanger that needs cooling.

As mentioned above, FIG. 2 is an illustrative example of multiple heat exchangers 200 according to some embodiments of the invention. In some embodiments, the heat exchanger 200 may be used with multiple hot spots (at each of cold plates 110A-B) thermal solution. The gates (not shown, but included as each exchanger of the exchanger 200 is an exchanger 100) may distribute the amount of fluid, such as air, blown from blower fan 212, and going into each heat exchanger 100A-B to achieve optimal cooling, especially at low platform power conditions, according to some embodiments of the invention.

In some embodiments, the heat exchanger 100 may include a tube 110 to transport a first fluid. According to some embodiments of the invention, the first fluid may be a liquid coolant, such as a distilled water, ethylene/propylene, or glycol mixture. Other types of liquid coolant, such as water or water with mixture of ions, may also be used, as long as they serve the function of cooling, as one of ordinary skill in the relevant art would appreciate based at least on the teachings provided herein.

Alternative types of tubing, such as heat pipes may be employed by some embodiments of the invention, and the above description is not intended to limit the scope of the embodiments. One of ordinary skill in the art would appreciate that heat pipes may be used, in accordance with some embodiments of the invention, based at least on the teachings provided herein.

As described above, in some embodiments, the heat exchanger 100 may also include a plurality of fins 102 coupled to the tube to facilitate transfer of thermal energy from the first fluid to the plurality of fins. In some embodiments, the plurality of fins may be arranged in a stack of mutually parallel plates. In some embodiments, the plurality of fins may be of an irregular shape or shapes, as one of ordinary skill in the relevant art would appreciate based at least on the teachings provided herein.

Furthermore, as described herein, the gate 106 may be coupled to the plurality of fins 102 to direct flow of a second fluid through passages between the fins. According to some embodiments, the gate may include a deformable laminate of a plurality of layers having different coefficients of thermal expansion, the plurality of layers being bonded to one another.

In some embodiments, the second fluid may be air, but in other embodiments other liquids or gases may be used, as one of ordinary skill in the relevant art(s) would appreciate based at least on the teachings provided herein.

According to some embodiments, the gate may be deformable towards one or more sides with changes in temperature. More specifically, in some embodiments, the gate may be deformable towards a contracted state at a low temperature, where the flow of the second fluid through the plurality of fins is reduced. In some embodiments, the gate may be deformable towards an expanded state at a high temperature, wherein the flow of the second fluid through the plurality of fins is increased.

More specifically, in some embodiments, the contracted state may include one of the layers having a higher coefficient of thermal expansion contracts to deform the gate toward the near side of the layer. Also, in some embodiments, the expanded state may include one of the layers having a higher coefficient of thermal expansion expands to deform the gate toward the far side of the layer.

The layers of the gate 106 may include various resins, metals, alloys, or other materials or combinations of materials, as one of ordinary skill in the relevant art would appreciate based at least on the teachings provided herein. For example, in some embodiments, ionomer resins, copolymer resins, emulsion resins, and other types of resins may be used. Also, in some embodiments, various metals, such as iron, steel, copper, aluminum, aluminum alloys, titanium, zinc, zirconium, brass, and/or lead, may be used.

In some embodiments, the layers are adjacent to one another and have different coefficients of thermal expansion. Based on the above materials, or similar equivalents, the differences in coefficients between the layers may be as small as 0.001% or as great as 30% or greater. In some embodiments, the materials, length and width of the layers, and the differences in coefficients of the materials in each of the layers, is chosen based on the temperature range likely to be experienced by the heat exchanger 100. As such, in some embodiments, the low temperature may be about −32 degrees Celsius and the high temperature may be about 100 degrees Celsius, as one of ordinary skill in the relevant art would appreciate based at least on the teachings provided herein.

According to some embodiments of the invention, the heat exchanger may be a condenser and be used with a compressor, evaporator, and throttling device, as one of ordinary skill in the art would appreciate based on the teachings contained herein.

FIG. 3 is a cross-sectional diagram of a cooling apparatus 300 with a heat exchanger 306 according to some embodiments of the invention. In some embodiments, the apparatus 300 may include a heat exchanger 306 including a tube 302 to transport a first fluid and a plurality of fins coupled to the tube to facilitate transfer of thermal energy from the first fluid to the plurality of fins. In some embodiment, a gate 308 may be coupled to the plurality of fins to direct flow of a second fluid through passages between the fins, where, in some embodiments, the gate may include a deformable laminate of a plurality of layers having different coefficients of thermal expansion. In some embodiments, the plurality of layers being bonded to one another. Furthermore, a cold plate 314 may be coupled to the tube and coupled to an electronic component (not shown) from which thermal energy is to be transferred.

In some embodiments, the apparatus 300 may include a blower 310. The blower 310 may be exposed to ambient air, and may be a axial flow fan, or a centrifugal blower fan, or another type of fan or fans, as one of ordinary skill in the relevant art would appreciate based at least on the teachings provided herein. Moreover, one of ordinary skill in the relevant art would appreciate how to implement the use of the fan in the apparatus 300, based at least on the teachings provided herein. A pump 304, powered by a battery or other power supply, may push the liquid through the tubing 302.

In some embodiments, a pump 304 may be coupled to the tube, where the pump 304 may circulate the first fluid through the tube between the cold plate and the heat exchanger. In embodiments of the invention, the tubing 302 may be flexible or rigid. It is noted that even a somewhat (or less than completely) flexible tubing may be preferably used to connect cold plate 314 and the pump 304 to the heat exchanger 306 because a flexible tubing may be easily routed around other components inside a system, such as, but not limited to a computer system, in which some embodiments of the apparatus 300 may operate and accommodate a greater number of system designs.

According to some embodiments of the invention, a cold plate 314 may provide for the transfer of a substantial amount of the thermal energy generated by one or more electronic components (see FIG. 4), and to be transferred to the heat exchanger 306. Furthermore, in some embodiments of the invention, the cold plate or a cold plate that includes a manifold plate (not shown) may be replaced with other types of heat sink(s). According to some embodiments of the invention, the cold plate 314 may be a thermally conductive block on which the electronic component may either directly mount or may be closely positioned for heat removal. In some embodiments, the thermally conductive block may be in the shape of a plate with one or more groove(s), a channel(s) or a thermally conductive tube(s) running through it.

FIG. 4 is a cross-sectional diagram of a system 400, such as a computer system, with a cooling apparatus 300 according to some embodiments of the invention. The system 400 may include an electronic component 416, described above, and shown here. The system 400 includes a frame (or chassis) 418 to contain the apparatus 300, the electronic component 416, and one or more air flow vents 420. In some embodiments, the air flow vents 420 are situated with respect to the apparatus 300 to provide for the intake and outtake of air, as one of ordinary skill in the relevant art would appreciate based at least on the teachings described herein.

When heat is generated by the electronic component 416, according to some embodiments of the invention, the heat may be transferred from the electronic component 416 to the cold plate 314. In some embodiments of the invention, the electronic component 416 may be directly attached to the surface of the cold plate 314. Preferably, in some embodiments of the invention, a thin highly conductive interface film material (not shown) is interposed between the electronic component 416 and the cold plate 314. This interface film material may be thermally conductive grease similar to, for example, Chomerics® T710 and Chomerics® T454 or some other substance which one of ordinary skill in the relevant art would appreciate based at least on the teachings described herein.

In some embodiments of the invention, the cold plate 314, which may include a manifold plate used with the cold plate, may include one or more microchannels, bumps, dimples, and/or posts, as one of ordinary skill in the relevant art would appreciate based at least on the teachings provided herein.

According to some embodiments of the invention, the electronic component 416 may be a core, where the core may include one or more microprocessors, or a chipset. In some embodiments of the invention, the electronic component 416 may be a silicon die, of any configuration, which is employed to perform operations and as a result or by-product of operating generates heat, and may be thus considered a heat generating component even though the primary purpose of the electronic component is not to generate heat.

In some embodiments of the invention, the components of the apparatus 300 may serve to cool the electronic components 416, which may be relatively hot during operation. In some embodiments of the invention, the electronic component 416 may be processors in a computer system with power dissipation, which requires a cooling solution. Without proper cooling, the electronic components 416 may break or cease function correctly.

Although only electronic component 416 is shown in FIG. 4, the frame or chassis 418 may include more than one electronic component, and may also be used to cool other type of devices or components that generate heat. For example, components of the frame 418 may be configured for dissipating heat from a hard disk unit or a power source used in an electronic apparatus. The frame 418 may also be used to dissipate heat from an integrated circuit package or the surface of a printed circuit board. Moreover, in some embodiments of the invention, the components of the frame 418, including the apparatus 300, may have surfaces contacting one another.

As described elsewhere herein, in some embodiments of the invention, a heat pipe (not shown) may be used either with or instead of the tubing 302, and may be of the type to provide ambient flow of thermal energy.

In alternative embodiments of the invention, the system 400 may include a plurality of components, including a plurality of electronic components 416, and more than one apparatus 300, each on a respective unit or combination of units. Furthermore, the system 400 may include a plurality of heat pipes, each for a respective cold plate 314, according to some embodiments of the invention. The use of heat pipes may allow for increases in the thermal design power (TDP) of the system 400, specifically at the electronic component 416. The system 400, therefore, may be afforded an decrease in overall power requirements as the pump 304, which requires power, will not have to operate as frequently as pump 108 in system 400 or in the apparatus 300 because the heat pipe (not shown) may provide an ambient or passive pathway for thermal energy to flow from the electronic component 416 to the heat exchanger 306.

It is noted that according to some embodiments of the invention, the electronic component 416, such as, but not limited to, a microprocessor, a core with one or more microprocessors, a hard drive, a circuit board, or more than one electronic component. It is also noted that according to one embodiment of the invention, the electronic component 416 does not always operate at its TDP. In certain circumstances, for example, when in a power conservation mode, the electronic component 416 may operate at power levels much lower than the TDP, such as, but not limited to, 10-15 Watts (W) or some other fraction of TDP. According to some embodiments of the invention, such as, but not limited to low power conditions, the embodiments of the invention may be capable of optimizing the dissipation the thermal energy generated by the electronic component 416 when operating at the fractional TDP.

FIG. 5 includes cross-sectional diagrams of various examples of deformable laminate gates according to some embodiments of the invention. The layers of the gates are shown as layer 504, 506, and 508, respectively. In some embodiments, layer 504 may be longer at low temperature than layer 506, while at higher temperatures they may be the same length, as shown at 502. Similarly, a three layer embodiment is shown.

According to some embodiments of the invention, combinations of one or more types of layers may be used with embodiments of the gate of the invention. Moreover, one or more layers may be altered or adjusted as shown in FIG. 5, to provide the changes in shape necessary to make provide the required flow of the second fluid, such as air, in some embodiments. The layers, in some embodiments, are not limited to those shown in FIG. 5, and may use more layers than are shown herein, as one of ordinary skill in the relevant art would appreciate based at least on the teachings described herein.

The materials and composition, as well as selection, of the layers are described elsewhere herein, such as with respect to FIG. 1, according to some embodiments of the invention.

FIG. 6 shows a flow diagram of the flow distribution process 600 according to some embodiments of the invention. The process 600, in some embodiments, may begin at 602 and proceed to 604, where the process 600 may determine a threshold temperature for a transition between a contracted state and an expanded state. In some embodiments, the operating temperature range of a system or apparatus may have a threshold temperature substantially at its center. In some embodiments, the process may proceed to 606, where it may determine one or more layers based on the threshold temperature. In some embodiments, the layers may be implemented at the heat exchanger in series, and the number of layers implemented may depend on the threshold temperature, as one of ordinary skill in the relevant art would appreciate based at least on the teachings provided herein. As such, the process 600 may then proceed to 608, where it may configure a gate with a plurality of layers including the one or more layers based on the threshold temperature.

According to some embodiments of the invention, the process 600 may proceed to 610, where it may direct the flow of a fluid through the gate, where the flow is reduced when the gate is in the contracted state. Alternatively, or at an earlier or later time, in some embodiments of the invention, the process 600 may proceed to 612, where the flow is increased when the gate is in the expanded state. The process 600 may then proceed to 614, where it may end, and it then free to proceed to any of the operations described above: 604, 606, 608, and/or 610, 612, as one of ordinary skill in the relevant art would appreciate based at least on the teachings provided herein.

FIG. 7 shows a flow diagram of the flow distribution process 700 according to some embodiments of the invention. The process 700 starts at 702 and may proceed to 704 and 706, where the process 700 may implement a first gate at a first heat exchanger and implement a second gate at a second heat exchanger, where the first and second heat exchangers share one or more blowers, respectively.

The process 700, in some embodiments, may proceed to 708, where it may contract the first gate in response to a reduction in heat energy at the first heat exchanger. The process 700 may proceed to 710, where it may direct a larger portion of the flow of a second fluid, such as but not limited to air, from the blower through the second gate, according to some embodiments of the invention. As such, in some embodiments, the multiple gates may therefore be used to more effectively direct the flow of the second fluid and allow for improved cooling and/or a reduction in the power requirements of at least the blower.

The process 700 may then end at 712, where, in some embodiments, it may repeat any of the operations 702, 704, 706, 708, and/or 710, as one of ordinary skill in the relevant art would appreciate based at least on the teachings provided herein.

Embodiments of the invention may be described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized, and structural, logical, and intellectual changes may be made without departing from the scope of the present invention. Moreover, it is to be understood that various embodiments of the invention, although different, are not necessarily mutually exclusive. For example, a particular feature, structure, or characteristic described in one embodiment may be included within other embodiments. Those skilled in the art can appreciate from the foregoing description that the techniques of the embodiments of the invention can be implemented in a variety of forms. Therefore, while the embodiments of this invention have been described in connection with particular examples thereof, the true scope of the embodiments of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims. 

1. A heat exchanger comprising: a tube to transport a first fluid; a plurality of fins coupled to the tube to facilitate transfer of thermal energy from the first fluid to the plurality of fins; and a gate coupled to the plurality of fins to direct flow of a second fluid through passages between the fins, wherein the gate includes a deformable laminate of a plurality of layers having different coefficients of thermal expansion, the plurality of layers being bonded to one another.
 2. The heat exchanger of claim 1, wherein the first fluid is a liquid or a solid.
 3. The heat exchanger of claim 1, wherein the second fluid is air.
 4. The heat exchanger of claim 1, wherein the plurality of fins is arranged in a stack of mutually parallel plates.
 5. The heat exchanger of claim 1, wherein the gate is deformable towards one or more sides with changes in temperature.
 6. The heat exchanger of claim 5, wherein the gate is deformable towards a contracted state at a low temperature, wherein the flow of the second fluid through the plurality of fins is reduced.
 7. The heat exchanger of claim 5, wherein the gate is deformable towards an expanded state at a high temperature, wherein the flow of the second fluid through the plurality of fins is increased.
 8. The heat exchanger of claim 6, wherein the contracted state includes one of the layers having a higher coefficient of thermal expansion contracts to deform the gate toward the near side of the layer.
 9. The heat exchanger of claim 7, wherein the expanded state includes one of the layers having a higher coefficient of thermal expansion expands to deform the gate toward the far side of the layer.
 10. An apparatus comprising: a heat exchanger including a tube to transport a first fluid; a plurality of fins coupled to the tube to facilitate transfer of thermal energy from the first fluid to the plurality of fins; a gate coupled to the plurality of fins to direct flow of a second fluid through passages between the fins, wherein the gate includes a deformable laminate of a plurality of layers having different coefficients of thermal expansion, the plurality of layers being bonded to one another; and a cold plate coupled to the tube and coupled to an electronic component from which thermal energy is to be transferred.
 11. The apparatus of claim 10, further comprising: a pump coupled to the tube, wherein the pump circulates the first fluid through the tube between the cold plate and the heat exchanger.
 12. The apparatus of claim 10, wherein the first fluid is a liquid or a solid.
 13. The apparatus of claim 10, wherein the second fluid is air.
 14. The apparatus of claim 10, wherein the plurality of fins is arranged in a stack of mutually parallel plates.
 15. The apparatus of claim 10, wherein the gate is deformable towards one or more sides with changes in temperature.
 16. The apparatus of claim 15, wherein the gate is deformable towards a contracted state at a low temperature, wherein the flow of the second fluid through the plurality of fins is reduced.
 17. The apparatus of claim 15, wherein the gate is deformable towards an expanded state at a high temperature, wherein the flow of the second fluid through the plurality of fins is increased.
 18. The apparatus of claim 16, wherein the contracted state includes one of the layers having a higher coefficient of thermal expansion contracts to deform the gate toward the near side of the layer.
 19. The apparatus of claim 17, wherein the expanded state includes one of the layers having a higher coefficient of thermal expansion expands to deform the gate toward the far side of the layer.
 20. A system comprising: a chassis including airflow vents; a plurality of components capable of generating heat, the components mounted within the chassis; and an apparatus including a heat exchanger including a tube to transport a first fluid; a plurality of fins coupled to the tube to facilitate transfer of thermal energy from the first fluid to the plurality of fins; a gate coupled to the plurality of fins to direct flow of a second fluid through passages between the fins, wherein the gate includes a deformable laminate of a plurality of layers having different coefficients of thermal expansion, the plurality of layers being bonded to one another; and a cold plate coupled to the tube and coupled to an electronic component from which thermal energy is to be transferred.
 21. The system of claim 20, further comprising: a second apparatus including a second heat exchanger including a second tube to transport a third fluid; a second plurality of fins coupled to the second tube to facilitate transfer of thermal energy from the third fluid to the second plurality of fins; a second gate coupled to the second plurality of fins to direct flow of a fourth fluid through passages between the fins, wherein the second gate includes a deformable laminate of a second plurality of layers having different coefficients of thermal expansion, the second plurality of layers being bonded to one another; and a second cold plate coupled to the second tube and coupled to a second electronic component from which thermal energy is to be transferred.
 22. The system of claim 21, wherein the first and third fluids are a liquid or a solid.
 23. The system of claim 21, wherein the second and fourth fluids are air.
 24. The system of claim 20, wherein the plurality of fins is arranged in a stack of mutually parallel plates.
 25. The system of claim 20, wherein the gate is deformable towards one or more sides with changes in temperature.
 26. The system of claim 25, wherein the gate is deformable towards a contracted state at a low temperature, wherein the flow of the second fluid through the plurality of fins is reduced.
 27. The system of claim 25, wherein the gate is deformable towards an expanded state at a high temperature, wherein the flow of the second fluid through the plurality of fins is increased.
 28. The system of claim 26, wherein the contracted state includes one of the layers having a higher coefficient of thermal expansion contracts to deform the gate toward the near side of the layer.
 29. The system of claim 27, wherein the expanded state includes one of the layers having a higher coefficient of thermal expansion expands to deform the gate toward the far side of the layer.
 30. A method comprising: determining a threshold temperature for a transition between a contracted state and an expanded state; determining one or more layers based on the threshold temperature; and configuring a gate with a plurality of layers including the one or more layers based on the threshold temperature.
 31. The method of claim 30, further comprising: directing flow of a fluid through the gate, wherein the flow is reduced when the gate is in the contracted state.
 32. The method of claim 31, wherein the flow is increased when the gate is in the expanded state. 